/**
 * Copyright (c) 2009 Sergiy Kovalchuk (serg472@gmail.com)
 *
 * Dual licensed under the MIT (http://www.opensource.org/licenses/mit-license.php)
 * and GPL (http://www.opensource.org/licenses/gpl-license.php) licenses.
 *
 * Following code is based on Element.mask() implementation from ExtJS framework (http://extjs.com/)
 *
 */
(function($){

    /**
	 * Displays loading mask over selected element(s). Accepts both single and multiple selectors.
	 *
	 * @param label Text message that will be displayed on top of the mask besides a spinner (optional).
	 * 				If not provided only mask will be displayed without a label or a spinner.
	 * @param delay Delay in milliseconds before element is masked (optional). If unmask() is called
	 *              before the delay times out, no mask is displayed. This can be used to prevent unnecessary
	 *              mask display for quick processes.
	 */
    $.fn.mask = function(label, delay){
        $(this).each(function() {
            if(delay !== undefined && delay > 0) {
                var element = $(this);
                element.data("_mask_timeout", setTimeout(function() {
                    $.maskElement(element, label)
                }, delay));
            } else {
                $.maskElement($(this), label);
            }
        });
    };

    /**
	 * Removes mask from the element(s). Accepts both single and multiple selectors.
	 */
    $.fn.unmask = function(){
        $(this).each(function() {
            $.unmaskElement($(this));
        });
    };

    /**
	 * Checks if a single element is masked. Returns false if mask is delayed or not displayed.
	 */
    $.fn.isMasked = function(){
        return this.hasClass("masked");
    };

    $.maskElement = function(element, label){

        //if this element has delayed mask scheduled then remove it and display the new one
        if (element.data("_mask_timeout") !== undefined) {
            clearTimeout(element.data("_mask_timeout"));
            element.removeData("_mask_timeout");
        }

        if(element.isMasked()) {
            $.unmaskElement(element);
        }

        if(element.css("position") == "static") {
            element.addClass("masked-relative");
        }

        element.addClass("masked");

        var maskDiv = $('<div class="loadmask"></div>');

        //auto height fix for IE
        if(navigator.userAgent.toLowerCase().indexOf("msie") > -1){
            maskDiv.height(element.height() + parseInt(element.css("padding-top")) + parseInt(element.css("padding-bottom")));
            maskDiv.width(element.width() + parseInt(element.css("padding-left")) + parseInt(element.css("padding-right")));
        }
        //当body的高度小于窗口的高度时，遮挡整个窗口
        if(element.is("body") && element.height()<$(window).height()){
            maskDiv.height($(window).height() + parseInt(element.css("padding-top")) + parseInt(element.css("padding-bottom")));
        }

        //fix for z-index bug with selects in IE6
        if(navigator.userAgent.toLowerCase().indexOf("msie 6") > -1){
            element.find("select").addClass("masked-hidden");
        }

        element.append(maskDiv);

        if(label !== undefined) {
            var maskMsgDiv = $('<div class="loadmask-msg" style="display:none;"></div>');
            maskMsgDiv.append('<div>' + label + '</div>');
            element.append(maskMsgDiv);
            //calculate center position
            var top = Math.round(element.height() / 2 - (maskMsgDiv.height() - parseInt(maskMsgDiv.css("padding-top")) - parseInt(maskMsgDiv.css("padding-bottom"))) / 2)+"px";
            var left = Math.round(element.width() / 2 - (maskMsgDiv.width() - parseInt(maskMsgDiv.css("padding-left")) - parseInt(maskMsgDiv.css("padding-right"))) / 2)+"px";

            if(element.is("body")){
                //top = Math.round($(window).height() / 2 - (maskMsgDiv.height() - parseInt(maskMsgDiv.css("padding-top")) - parseInt(maskMsgDiv.css("padding-bottom"))) / 2)+"px";
                top = Math.round($(document).height()-$(window).height()+$(window).height()/2)+"px";
           }
            maskMsgDiv.css("top", top);
            maskMsgDiv.css("left", left);

            maskMsgDiv.show();
        }

    };

    $.unmaskElement = function(element){
        //if this element has delayed mask scheduled then remove it
        if (element.data("_mask_timeout") !== undefined) {
            clearTimeout(element.data("_mask_timeout"));
            element.removeData("_mask_timeout");
        }

        element.find(".loadmask-msg,.loadmask").remove();
        element.removeClass("masked");
        element.removeClass("masked-relative");
        element.find("select").removeClass("masked-hidden");
    };

})(jQuery);